Competitive endogenous RNA-mediated upregulation of PLOD2 expression correlates with poor prognosis and tumor immune infiltration of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSC) is the most common malignant lesion of the head and neck. Immune infiltration may guide research on the development of immunotherapeutic strategies to treat HNSC. Procollagen-lysine,2-oxoglutarate 5-dioxygenase 2 (PLOD2) may be involved in the progression of HNSC. However, the function and mechanism of PLOD2 in HNSC is unknown. We analyzed PLOD2 expression and prognosis of patients with HNSC using The Cancer Genome Atlas data. Subsequently, we identified noncoding RNAs that contributed to the overexpression of PLOD2 through a combination of in silico analyses, including correlation analysis, expression analysis, and survival analysis. Furthermore, we investigated the relationship between the expression of PLOD2 and immune cell infiltration of tumors. This analysis revealed the potential of PLOD2 to function as an oncogene in HNSC. A competitive endogenous RNA (ceRNA) mechanism involving the lncRNA AC104088.1 and miR-26b-5p was identified as a potential regulator. Moreover, the level of PLOD2 expression was significantly and positively associated with immune cell infiltration of tumors, biomarkers of immune cells, and poor prognosis associated with tumor-infiltrating immune cell populations. Our findings indicate that ceRNA-mediated upregulation of PLOD2 is associated with poor prognosis and immune cell infiltration in HNSC.